This application relates to tunable lasers. More specifically, and without limitation, to tunable semiconductor lasers using binary super gratings (BSGs). Silicon integrated circuits (“ICs”) have dominated the development of electronics and many technologies based upon silicon processing have been developed over the years. Their continued refinement led to nano-scale feature sizes that can be important for making metal oxide semiconductor CMOS circuits. On the other hand, silicon is not a direct-bandgap material. Although direct-bandgap materials, including III-V compound semiconductor materials, have been developed, there is a need in the art for improved methods and systems related to photonic ICs utilizing silicon substrates.